Meeting Abstract

47.10  Jan. 6  Ectoparastic Infestation and Impaired Endocrine Stress Responsiveness in Marine Fishes in the Southern California Bight KALMAN, J.E.**; REYES, J.A.; ARMSTRONG, J.L.; SAK, K.; KELLEY, K.M.; California State University, Long Beach; California State University, Long Beach; Orange County Sanitation District, Fountain Valley, CA; California State University, Long Beach; California State University, Long Beach jkalman@csulb.edu

The southern California marine environment is subjected to numerous inputs of pollution, but little is known about pollution effects on infestation of parasites on fishes. Poor water quality and pollution exposure can be chronic stressors, potentially decreasing a fish�s defense systems and increasing its susceptibility to diseases and parasites, while disease and/or parasitic infestation will further exacerbate the stressed condition. Pollutants may also have direct effects upon several targets along the neuroendocrine hypothalamo-pituitary-interrenal (HPI) axis, affecting production of the stress hormone, cortisol. We evaluated marine fish and parasite species as potential bioindicators of environmental stress, and also assessed the ability of the HPI axis to normally respond to delivered stressors. Selected marine fish species were collected by trawling from stations adjacent to and away from the four largest wastewater treatment plant (WWTP) outfalls in southern California, and were inspected for ectoparasitic infestation. Many parasites exhibited high host specificity, while the rates of infestation varied according to host fish species suggesting that some fish species may be more resistant to parasitization or have evolutionarily lost their parasites. Interestingly, several fish species, when sampled from locations in the vicinity of WWTP outfalls, exhibited relatively higher parasite prevalence coincidentally with significantly impaired function of their HPI axis, as they could not produce normal surges in cortisol in response to catching stress.